What Is a DNG File? Adobe's Open RAW Format Explained
A .DNG file is a Digital Negative: Adobe's attempt at a RAW format that is not tied to one manufacturer. Its specification is published, which is the whole point — a CR3 or an ARW can only be read by software someone chose to write a decoder for, and that choice may not outlive the camera.
The confusing part is that two very different things share the extension. Some cameras write DNG natively. Other DNGs are conversions of a manufacturer's RAW file. They behave differently and the distinction matters.
Native DNG and converted DNG
A native DNG is what the camera wrote. Leica, Pentax, Ricoh, Sigma, DJI drones and Apple's ProRAW all produce them directly, and for those cameras DNG simply is the RAW format — there is no other version of the file.
A converted DNG is what Adobe's free DNG Converter produces from a NEF, CR3, ARW or similar. The sensor data comes across losslessly, so nothing is degraded, but this is a translation rather than the original document.
The practical difference is metadata. Manufacturer-specific information — Nikon's Picture Controls, Fujifilm's film simulations, some lens-correction data, various maker notes — has no standard place to live in a DNG. Adobe's converter preserves what it can, but software downstream may not know how to use it.
Why anyone converts
Three reasons, in descending order of how often they apply.
Compatibility: a camera released last month may not open in your converter for weeks. DNG conversion is the standard stopgap, because almost everything reads DNG.
Self-contained edits. This is the one photographers feel day to day. Edits to a proprietary RAW live in a separate sidecar file — an .xmp next to the .NEF — and if the two are separated, the edits are gone. A DNG stores them inside the file itself, so moving one file moves everything.
Longevity. An open, published specification is a better bet across decades than an undocumented one, which is the archival argument institutions make.
Mosaic, linear and lossy DNG
A normal DNG holds mosaic data — the raw sensor readings before demosaicing, exactly like the file it came from. This is the form that keeps all the flexibility of RAW.
A linear DNG has already been demosaiced: the colour reconstruction is done and baked in. Some converters produce these, and some cameras with unusual sensor layouts write them. They remain high-bit-depth and editable, but the demosaicing decision has been made for you and cannot be revisited.
There is also a lossy DNG option, which applies JPEG-style compression to the image data for dramatically smaller files. It is a real compromise and worth choosing deliberately rather than by accident — it is the one setting in the DNG Converter that discards information.
Embedding the original
The DNG Converter can embed the complete original RAW file inside the DNG it produces. The result is larger than either file alone, but it means the conversion is fully reversible: the original can be extracted later, byte for byte.
For anyone converting an archive, this removes most of the risk from the decision. You keep the open format's advantages without betting that nothing was lost in translation.
Frequently asked questions
Does converting to DNG lose quality?
No, unless you choose the lossy DNG option. The sensor data is transferred with lossless compression and produces identical results. What can be lost is manufacturer-specific metadata that has no standard representation in DNG.
Should I convert my RAW files to DNG?
It depends on what you value. Convert if you want edits stored inside the file rather than in sidecars, or if you are archiving for the long term and want an open format. Do not convert if you rely on manufacturer software or on features that read maker-specific metadata. Embedding the original removes most of the downside if you are unsure.
Is DNG smaller than a manufacturer's RAW?
Usually somewhat, because Adobe's lossless compression is often more efficient than what a camera applies in real time. The saving is modest — typically 10 to 20% — and disappears if you embed the original, which makes the file larger than both.
What is the difference between DNG and a .dcp camera profile?
A DNG is an image file. A DCP is a colour profile that tells a converter how to interpret one — the matrices and curves that turn sensor readings into meaningful colour. They share lineage in Adobe's DNG specification but do entirely different jobs.
Why does my iPhone ProRAW file open as a DNG?
Because it is one. ProRAW is Apple's use of the DNG specification, with computational-photography results written into the format. It is a native DNG, not a conversion, and includes more processing than a conventional RAW does.
Can I convert a DNG back to CR3 or NEF?
Only if the original was embedded at conversion time, in which case it can be extracted intact. Otherwise no — the manufacturer's container cannot be reconstructed from the DNG, even though the image data is all there.
Drop a DNG into RawCut's metadata reader to see whether it is mosaic or linear, what it was converted from, and its full EXIF.
Inspect a DNG